Cryogenic separation cold box micro-negative pressure circulation purification device
By incorporating a built-in air duct and a composite insulation layer, the temperature fluctuation problem caused by external circulation pipes is solved, achieving stable operation and efficient purification of the cryogenic separation cold box.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN FUDING INTELLIGENT CONTROL CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-05-12
AI Technical Summary
In existing cryogenic separation cold box micro-negative pressure circulation purification devices, the external circulation pipes are easily affected by ambient temperature, causing temperature fluctuations inside the cold box and affecting the efficient recovery of cold energy by the plate-fin heat exchanger.
It adopts an internal gas guide tube and a composite insulation layer, combined with an insulation shell made of metal frame and perlite interwoven filling material to reduce heat exchange between the pipeline and the external environment. With the help of three or more stages of gradually changing pore size filter screen and modular sealing components, it can achieve directional gas flow and precise temperature control.
It significantly reduces internal temperature fluctuations in the cold box, improves gas purification efficiency, avoids localized temperature buildup, and ensures stable operation of the cold box in ultra-low temperature environments.
Smart Images
Figure CN224221064U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of cold box technology, and in particular to a micro-negative pressure circulation purification device for cryogenic separation cold boxes. Background Technology
[0002] Cryogenic separation cold boxes are a type of enclosed equipment that integrates high-efficiency heat exchangers, low-temperature separation components, and insulation systems. By cooling the gas to below -100°C (up to -196°C in extreme conditions), they utilize the boiling point differences between components to achieve condensation, liquefaction, and stepwise purification.
[0003] Currently, a Chinese patent discloses a cryogenic separation cold box micro-negative pressure circulation purification device (authorization announcement number CN219976891U). The circulation air supply mechanism includes a suction fan, a first circulation pipe, and a second circulation pipe. A fixing plate is welded to one side of the cryogenic separation box. The bottom of the suction fan is fixed to one side of the fixing plate with screws. The two ends of the first circulation pipe are respectively connected to the top of the suction fan and the inside of the filter box to extract gas. The two ends of the second circulation pipe are respectively connected to the bottom of the suction fan and the inside of the cryogenic separation box to transport gas. A support plate is fixed to the outer surface of the cryogenic separation box with screws. The other end of the support plate is connected to the outer surface of the first circulation pipe for support and reinforcement. The circulation air supply mechanism is located on top of the filter assembly.
[0004] The current system uses an external circulation pipe in conjunction with a fan for gas transport. Although it can achieve the function of gas circulation and purification, the temperature of the gas flowing through the circulation pipe is easily affected by the ambient temperature and rises because the circulation pipe is exposed to the external environment. This will cause fluctuations in the internal temperature of the cold box, which in turn will affect the efficient recovery of the exhaust gas cooling capacity by the plate-fin heat exchanger. Utility Model Content
[0005] Therefore, it is necessary to provide a micro-negative pressure circulation purification device for cryogenic separation cold boxes, which addresses the problem of increased internal temperature fluctuations in existing cryogenic separation cold box micro-negative pressure circulation purification devices.
[0006] A micro-negative pressure circulation purification device for a cryogenic separation cold box includes:
[0007] The heat insulation shell has an airflow circulation chamber at its bottom and an insertion cavity at its top.
[0008] A composite insulation layer, wherein the composite insulation layer is a component consisting of a metal frame and a perlite interwoven filler material;
[0009] A circulation pump is embedded in the inner side of the airflow circulation chamber, with the air inlet of the circulation pump facing the chamber.
[0010] Two built-in air guide tubes are fixedly connected to the bottom of the heat insulation shell, and the two built-in air guide tubes are respectively connected to two openings of the airflow circulation chamber.
[0011] A filter mechanism is installed inside the cavity.
[0012] In one embodiment, the filtration mechanism includes a collection box inserted into the cavity, with air holes at both ends of the collection box communicating with the airflow circulation cavity, and a filter screen embedded in the air hole near the circulation pump.
[0013] In one embodiment, the number of the insertion chambers and the filtering mechanism are the same and not less than three, and the mesh diameter of the filter screen is larger than the mesh diameter of the filter screen adjacent to the circulation pump.
[0014] In one embodiment, the top of the collection box is fixedly connected to a protective cover that contacts the heat-insulating shell, and the protective cover is larger than the horizontal cross-sectional dimension of the cavity.
[0015] In one embodiment, a screw is rotatably connected to the top of the protective cover, and the bottom of the screw passes through the protective cover and the collection box in sequence and is threadedly connected to the cavity.
[0016] In one embodiment, a throttle is fixedly connected to the top of the screw, and the corners of the throttle are rounded.
[0017] In one embodiment, the top of the protective cover is fitted with a square-shaped sealing ring that contacts the heat insulation shell, and the cavity is located inside the square-shaped sealing ring.
[0018] In one embodiment, the end of the collection box facing away from the filter screen is fixedly connected to an annular sealing ring that contacts the insertion cavity, and the connection between the insertion cavity and the air hole facing away from the circulation pump is located inside the annular sealing ring. Beneficial effects
[0019] The aforementioned cryogenic separation cold box micro-negative pressure circulation purification device replaces the traditional external pipeline with an internal air guide pipe, significantly reducing the heat exchange interface between the pipeline and the external environment. Combined with the heat conduction suppression capability of the metal frame-perlite composite insulation layer, it significantly reduces the risk of temperature fluctuations inside the cold box. The micro-negative pressure circulation design allows the gas to flow in a directional manner, avoiding local temperature accumulation. With the modular sealing components, the overall system achieves precise maintenance of the ultra-low temperature environment of the cold box.
[0020] Equipped with three or more stages of gradually changing pore size filters, it forms a progressively intercepting solid impurities filtration gradient, effectively avoiding sudden pressure changes caused by blockage of a single filter layer. Furthermore, the quick-assembly and disassembly structure of the collection box, linked by a rotating screw, significantly improves the speed at which staff can maintain the filter structure. Attached Figure Description
[0021] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0022] Figure 1 This is a schematic diagram of the overall structure of this utility model;
[0023] Figure 2 This is a schematic diagram showing the connection between the overall structure and the cryogenic separation cold box in this utility model;
[0024] Figure 3 This is a cross-sectional schematic diagram of the cryogenic separation cold box of this utility model;
[0025] Figure 4 This is an exploded view of the filtration mechanism in this utility model.
[0026] Figure label:
[0027] 100. Insulated outer shell; 110. Air circulation chamber; 120. Insertion cavity; 200. Composite insulation layer; 300. Circulation pump; 400. Built-in air guide tube; 500. Filter mechanism; 510. Collection box; 520. Air hole; 530. Filter screen; 540. Protective cover; 550. Screw; 560. Thruster; 570. Square frame sealing ring; 580. Circular sealing ring. Detailed Implementation
[0028] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0029] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this specification are for illustrative purposes only and do not represent the only possible implementation.
[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0031] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0032] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this specification belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.
[0033] The following is combined Figures 1-4 This invention describes a cryogenic separation cold box micro-negative pressure circulation purification device.
[0034] In one embodiment, a cryogenic separation cold box micro-negative pressure circulation purification device includes:
[0035] The heat insulation shell 100 has an airflow circulation chamber 110 at its bottom and an insertion cavity 120 at its top.
[0036] The composite insulation layer 200 is a component consisting of a metal frame and perlite interwoven filling material. The metal frame supports the load and disperses the stress, while the perlite fills the gaps, synergistically reducing heat conduction. The anti-corrosion design of the frame, combined with the low moisture absorption of the perlite, enhances durability. Modular construction facilitates maintenance. This structure is lightweight, flame-retardant, and anti-static, with low overall cost, thereby reducing the probability of temperature fluctuations inside the cold box.
[0037] A circulation pump 300 is embedded in the inner side of the airflow circulation chamber 110, with the air inlet of the circulation pump 300 facing the insertion chamber 120.
[0038] Two built-in air guide pipes 400 are fixedly connected to the bottom of the heat insulation shell 100. The two built-in air guide pipes 400 are respectively connected to the two openings of the airflow circulation chamber 110. The design of built-in air guide pipes 400 can replace the existing external pipelines with internal ones, which not only effectively reduces the amount of pipeline used, but also reduces the influence of the external environment on the pipelines, thereby reducing the probability of temperature fluctuation inside the cold box.
[0039] The filter mechanism 500 is installed inside the cavity 120.
[0040] like Figure 3 and Figure 4 As shown, the filter mechanism 500 includes a collection box 510 inserted into the cavity 120. Both ends of the collection box 510 have air holes 520 communicating with the airflow circulation chamber 110. A filter screen 530 is embedded inside the air hole 520 near the circulation pump 300. The number of cavities 120 and the filter mechanism 500 is the same and not less than three. The mesh diameter of the filter screen 530 is larger than the mesh diameter of the adjacent filter screen 530 near the circulation pump 300. A protective cover 540 is fixedly connected to the top of the collection box 510, contacting the heat insulation shell 100. The protective cover 540 is larger than the horizontal cross-sectional dimension of the cavity 120. The top of the protective cover 540 can rotate. A screw 550 is connected, with its bottom passing through the protective cover 540 and the collection box 510 and threadedly connected to the cavity 120. A handle 560 is fixedly connected to the top of the screw 550, with rounded corners. A square-shaped sealing ring 570 that contacts the heat insulation shell 100 is embedded in the top of the protective cover 540, and the cavity 120 is located inside the square-shaped sealing ring 570. An annular sealing ring 580 that contacts the cavity 120 is fixedly connected to the end of the collection box 510 facing away from the filter screen 530, and the connection between the cavity 120 and the air hole 520 facing away from the circulation pump 300 is located inside the annular sealing ring 580.
[0041] In this embodiment, when the circulating pump 300 draws gas from inside the cold box through the airflow circulation chamber 110 and the built-in air guide pipe 400, creating a slight negative pressure inside the cold box, the drawn gas enters the insertion chamber 120 through the airflow circulation chamber 110 and enters the collection box 510 through the corresponding air hole 520. At the same time, the filter screen 530 filters solid impurities mixed in the airflow. As the airflow gets closer to the circulating pump 300, it is filtered by the filter screen 530 with smaller mesh diameter. This can gradually filter solid impurities mixed in the airflow. Finally, the circulating pump 300 delivers the clean gas that meets the requirements back to the cold box through another built-in air guide pipe 400 to achieve the effect of circulation purification.
[0042] When staff regularly maintain and clean the solid impurities inside the collection box 510, they first vent the gas from the cold box, then turn the handle 560 in the corresponding direction. The handle 560 drives the screw 550 to spiral upward along the connection with the insertion cavity 120. The screw 550 drives the collection box 510 to move upward along the inside of the insertion cavity 120. When the screw 550 is completely separated from the insertion cavity 120, the staff can open the unobstructed collection box 510 and then perform a centralized cleaning operation on the solid impurities in the collection box 510.
[0043] It should be noted that cryogenic separation cold boxes include, but are not limited to, the following structures:
[0044] Plate-fin heat exchanger: It is composed of multiple layers of aluminum alloy plates and fins stacked together to achieve efficient heat exchange of multiple fluids. It has the characteristics of high compactness and high heat exchange efficiency.
[0045] Low-temperature separation equipment includes multi-stage distillation columns, separation tanks, etc., used to separate liquefied gas components under different temperature gradients.
[0046] Insulated cold box: Filled with perlite or using a vacuum sandwich structure to effectively reduce the transfer of external heat and maintain the ultra-low temperature environment inside the cold box. The insulating outer shell 100 is welded to the top of the insulated cold box. Both ends of the built-in air duct 400 penetrate into the interior of the insulated cold box and extend to the corresponding preset positions. The specific installation position needs to be installed in a corresponding staggered manner according to the location to be purified and the original internal structure to ensure that the cold box structure can operate normally.
[0047] Low-temperature resistant piping system: Made of stainless steel or aluminum alloy to ensure that it will not crack under extreme low temperatures, and connects each heat exchanger and separation unit.
[0048] Operation process of cryogenic separation cold box:
[0049] Compression and purification: The gas is pressurized to 5-7 MPa by the compressor, and then passes through a dryer and molecular sieve to remove impurities such as moisture and carbon dioxide, preventing freezing and clogging of pipelines at low temperatures.
[0050] Pre-cooling and liquefaction: The purified gas enters the plate-fin heat exchanger and is gradually cooled to near the liquefaction temperature. Some of the gas is liquefied in the cold box to form liquid or liquid hydrocarbons.
[0051] Fractionation and separation: The liquid mixture enters the distillation column and is separated step by step by utilizing the difference in boiling points of the components; the separated liquid products are further purified and then output.
[0052] Cooling cycle: The separated low-temperature exhaust gas recovers its cooling capacity through a heat exchanger to pre-cool newly entering gas and reduce overall energy consumption; some processes use expanders for further cooling.
[0053] It should be noted that the circulating pump 300 and the cryogenic separation cold box mentioned above are both devices with relatively mature existing technologies. The specific model can be selected according to actual needs. At the same time, the circulating pump 300 and the cryogenic separation cold box can be powered by the built-in power supply or by the mains power. The specific power supply method should be selected according to the situation, which will not be elaborated here.
[0054] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0055] The above-described embodiments are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the appended claims.
Claims
1. A micro-negative pressure circulation purification device for a cryogenic separation cold box, characterized in that, include: The heat insulation shell (100) has an airflow circulation cavity (110) at its bottom and an insertion cavity (120) at its top. A composite insulation layer (200) is a component consisting of a metal frame and a perlite interwoven filling material. A circulation pump (300) is embedded in the inner side of the airflow circulation chamber (110), with the air inlet of the circulation pump (300) facing the insertion chamber (120). Two built-in air guide tubes (400) are fixedly connected to the bottom of the heat insulation shell (100), and the two built-in air guide tubes (400) are respectively connected to two openings of the airflow circulation chamber (110); A filter mechanism (500) is installed inside the cavity (120).
2. The cryogenic separation cold box micro-negative pressure circulation purification device according to claim 1, characterized in that, The filtration mechanism (500) includes a collection box (510) inserted into the cavity (120). Both ends of the collection box (510) are provided with air holes (520) that communicate with the airflow circulation cavity (110). A filter screen (530) is embedded in the air hole (520) near the circulation pump (300).
3. The cryogenic separation cold box micro-negative pressure circulation purification device according to claim 2, characterized in that, The number of the insertion cavity (120) and the filter mechanism (500) are the same and there are no less than three of each. The mesh diameter of the filter screen (530) is larger than the mesh diameter of the filter screen (530) adjacent to the circulation pump (300).
4. The cryogenic separation cold box micro-negative pressure circulation purification device according to claim 2, characterized in that, The top of the collection box (510) is fixedly connected to a protective cover (540) that contacts the heat insulation shell (100), and the protective cover (540) is larger than the horizontal cross-sectional dimension of the cavity (120).
5. The cryogenic separation cold box micro-negative pressure circulation purification device according to claim 4, characterized in that, The top of the protective cover (540) is rotatably connected to a screw (550), and the bottom of the screw (550) passes through the protective cover (540) and the collection box (510) in sequence and is threadedly connected to the insertion cavity (120).
6. The cryogenic separation cold box micro-negative pressure circulation purification device according to claim 5, characterized in that, The top of the screw (550) is fixedly connected to a throttle (560), and the corners of the throttle (560) are rounded.
7. The cryogenic separation cold box micro-negative pressure circulation purification device according to claim 4, characterized in that, The protective cover (540) has a square-shaped sealing ring (570) embedded in its top, which contacts the heat insulation shell (100), and the cavity (120) is located inside the square-shaped sealing ring (570).
8. The cryogenic separation cold box micro-negative pressure circulation purification device according to claim 2, characterized in that, The collection box (510) is fixedly connected to an annular sealing ring (580) that contacts the insertion cavity (120) at one end facing away from the filter screen (530). The connection between the insertion cavity (120) and the air hole (520) of the back circulation pump (300) is located inside the annular sealing ring (580).